Classic Confusion about the story

A few days ago I started playing WoW and I've landed on a shaman,been having a blast,but I'm very confused about the leveling process. When I unlocked Adventure Guide,I picked a quest and went to start it,but on my way I encountered Sylvanas reviving the dead and an Orc calling her a lunatic for it. I feel like I stumbled on a random story moment that I have no context for. Did I do something wrong? via /r/wow https://ift.tt/33TawQ4